Weathering The breakdown do the materials of Earth’s crust into smaller pieces.
Physical Weathering Process by which rocks are broken down into smaller pieces by external conditions. Types of Physical weathering –Frost heaving and Frost wedging –Plant roots –Friction and impact –Burrowing of animals –Temperature changes
Oxygen Iron combines with oxygen in the presence of water in a processes called oxidation The product of oxidation is rust
Carbon Dioxide CO 2 dissolves in rain water and creates carbonic acid Carbonic acid easily weathers limestone and marble
Living Organisms Lichens that grow on rocks produce weak acids that chemically weather rock
Acid Rain Compounds from burning coal, oil and gas react chemically with water forming acids. Acid rain causes very rapid chemical weathering
Warm-up What are the 2 types of weathering? Give examples for each. http://www.youtube.com/watch?v=yZkqNH Gu4ys
Karst Topography A type of landscape in rainy regions where there is limestone near the surface, characterized by caves, sinkholes, and disappearing streams. Created by chemical weathering of limestone